Length matching in T-structure ( i.e address in DDR2 with multiple chips)

Is there any way to set length rules to segments instead of nets in order to match a T-structure like an address tree in ddr2?

Maybe this is of any interest:

Kicad - Differential pair routing and trace length matching

I already saw that video but it does not explain if it is possible to measure segment length instead of track length

What do you mean by trace length and segment length? The matcher currently is capable of adjusting the length of a trivial connection (= track segments + vias between fanout points or pads). The tuned path is indicated with a yellow line.

suppose you have one ddr2 interface that drives two ddr2 chips; you have, in this case the address lines made of three segments arranged in a T shape, my question is if it is possible to measure each segment of these nets

Yes, it is how the length tuner works, it takes the segments/vias between two pads or junctions (tees). Clicking on the 3 tracks going out of the junction point on your DDR address lines will let you tune their lengths independently.

Ok, but each branch of the T structure inherits the same target length. is there a way to avoid this ( place a different rule for each branch?

Yes, just R-click->Length Tuning settings and type in the length you want.Unfortunately there’s no possibility to place constraints/directives on the schematic yet…